Separation, biochemical characterization and salt‐tolerant mechanisms of alkaline protease from <i>Aspergillus oryzae</i>

Pan, Zhongli; Yin, Yiyun; Yan, Jun; Zhang, Junke; Ma, Haile; Zhou, Cunshan

doi:10.1002/jsfa.9553

Cited by 32 publications

(27 citation statements)

References 31 publications

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“…Soy sauce is one of the most widely accepted traditional fermented soybean products owing to its unique taste, aroma and nutritional content. It is mainly produced from the whole soybeans or the defatted soybeans via fermentation using Aspergillus oryzae 1 . Soy sauce fermented from different raw materials (whole soybeans or defatted soybeans) can cause differences in taste, odor, color, nutrition and price.…”

Section: Introductionmentioning

confidence: 99%

Comparative study on the novel umami‐active peptides of the whole soybeans and the defatted soybeans fermented soy sauce

et al. 2020

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BACKGROUND Two kinds of soy sauce produced via fermentation of the whole soybeans and the defatted soybeans (soy sauce termed ‘SSS’ and ‘SSD’, respectively) were subjected to the treatment using aqueous ethanol solutions with high concentrations. Then tasty peptides were separated from SSS and SSD by sensory guided fractionation, using macroporous resin and reverse‐phase high‐performance liquid chromatography (RP‐HPLC), and identified by ultra‐performance liquid chromatography quadrupole time‐of‐flight tandem mass spectrometry (UPLC‐Q‐TOF‐MS/MS). Results The result showed that umami‐active fractions and ≤ 3 kDa peptides were mainly concentrated in the supernatants resulted from the treatment with 60% ethanol and the precipitates resulted from the treatment with 80% ethanol. The contents of ammonia nitrogen, non‐salt solids, bitter amino acids, amino acids in peptides and the proportion of ≤ 3 kDa peptides in SSS were higher than those in SSD. Sixteen and fourteen tasty peptides were separated from SSS and SSD, among them five dipeptides (γ‐Glu‐Glu, Glu‐Glu, γ‐Glu‐Cys, γ‐Glu‐Leu, Glu‐Leu and Ile‐Glu) with a glutamic acid residue were identified both in SSS and SSD, which have been reported as umami/kokumi‐active peptides in soy sauce. Several peptides identified from SSS (Thr‐Gly‐Cys, Gly‐Leu‐Glu, Val‐Glu‐Ala‐Leu and Gly‐Gly‐Gly‐Glu) and SSD (Asp‐Arg, Asp‐Ala‐Glu, Glu‐Val‐Cys and Gly‐Gly‐Gly‐Glu) are tasty and/or umami‐active peptides but have not been reported as tasty peptides in the past. Conclusion Most of the peptides separated from SSD and SSS could impart an umami‐enhancing effect on soy sauce, and the marginally more kokumi and bitterness hydrophobic peptides were found in SSS than SSD. © 2020 Society of Chemical Industry

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Section: Introductionmentioning

confidence: 99%

Comparative study on the novel umami‐active peptides of the whole soybeans and the defatted soybeans fermented soy sauce

et al. 2020

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“…Loss of essential water was a possible cause of enzyme deactivation due to the collapse of the ordered secondary structure. The high proportion of ordered secondary structures of AOIM was benefit to keep good stability in high salinity (Gao et al, 2019), the same as in this trace water-in-oil system.…”

Section: Effect Of the Trace Water-in-oil Medium On The Conformation Of Four Lipasesmentioning

confidence: 75%

“…The AOIM model protease (PDB accession no. 4K90.pdb, 81% similarity) indicated the highest similarities to non-salt-tolerant neutral protease, which was isolated from A. oryzae 3.042 (Gao et al 2019). The lipase crystal structures with original crystal water (treated as the trace water) were added in a box with a size of 7.292 × 7.615 × 7.533 nm using a minimum distance of 12 Å between the box boundary and the protein.…”

Section: Molecular Dynamics Simulation For the Catalyzed Reactionmentioning

confidence: 99%

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Stability comparison of four lipases and catalytic mechanism during the synthesis of 1,3‐di‐oleic‐2‐medium chain triacylglycerols in a trace water‐in‐oil system: Experimental analyses and computational simulations

Peng

Luo

Wang³

et al. 2021

J Food Biochem

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In the present study, a kind of structured lipids, namely 1,3-di-oleic-2-medium chain (OMO) triacylglycerols, were synthesized through lipase-catalyzed reactions using coconut oil and rapeseed acid as materials in a trace water-in-oil system. Experimental analysis and computational simulations were undertaken to compare the stability of four lipases including Lipozyme RMIM, Lipozyme TLIM, Novozym 435, and Aspergillus oryzae immobilized lipase (AOIM), and illustrate catalytic mechanism of Novozym 435 during the synthesis of OMO. Fourier transform infrared and molecular dynamics simulation results demonstrated that a decrease in ordered structure (α-helix and β-sheet) led to a reduction in enzyme activity. Compared with Lipozyme RMIM and Novozym 435, Lipozyme TLIM and AOIM exhibited better stability due to a short-chain lid in TLIM, which covers activity sites, and hydrogen bonds formed between activity center of AOIM and water. Among four lipases, AOIM exhibited best catalytic performance: a OMO yield of 30.7% at 3 hr and a good stability of long term (48 hr). Density functional theory results demonstrated that specifically, during the synthesis of OMO triacylglycerol, the addition of Novozym 435 (derived from Candida antarctica lipase B, CALB) substantially lowered reaction barriers (64.4 KJ/ mol with CALB vs. 332.7 KJ/mol with no lipase), aiding in the generation of OMO because of the formations of transitional tetrahedral intermediates. A trace waterin-oil system was a green and efficient alternative for lipase-catalyzed production of OMO, and this study provided crucial insights into the stability/instability and catalytic mechanisms of lipase in the synthesis of structured lipids. Practical applicationsWe compared the stability of Lipozyme RMIM, Lipozyme 435, Lipozyme TLIM, and AOIM during the synthesis of the OMO triacylglycerols in a trace water-in-oil system, where exhibited a high catalytic activity of lipase in water-oil interface. AOIM had the highest stability and showed the best catalytic performance due to the formation of hydrogen bonds. Besides, for the first time, the transition tetrahedral structure was revealed in the enzymatic synthesis of medium-and long-chain triacylglycerols.

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“…Halotolerant enzymes are commonly produced by halotolerant microorganisms (Graziano and Merlino, 2014). For example, Gao et al (2019) reported that the proteases secreted by Aspergillus oryzae was more stable than non-salttolerant proteases at high salinity, remaining 20% active even in the presence of 3.0 mol L −1 NaCl after 7 days (Gao et al, 2019). An protease was also isolated from the halotolerant organism Lycinibacillus macrolides, with activity of 304 U mL −1 in highly saline conditions (>4%) (Pounsamy et al, 2017).…”

Section: Bioaugmentation Using Enzymes As Biodegrading Agentsmentioning

confidence: 99%

Options for Improved Treatment of Saline Wastewater From Fish and Shellfish Processing

Anh

Shahsavari

Bott

et al. 2021

Front. Environ. Sci.

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The rapid growth of the aquaculture industry over recent decades, with annual production reaching 94.6 million tonnes in 2018 has resulted in a significant increase in saline wastewater following the use of seawater in both fish and shellfish production and processing. This wastewater contains high concentrations of nutrients, organic compounds, and total nitrogen, resulting in the requirement for significant treatment prior to discharge to meet environmental regulations, which are becoming more stringent. The infrastructure and running costs associated with physico-chemical treatment approaches are generally higher than the implementation of biological approaches; the latter represents both an economic and sustainable technology. However, salinity represents a significant inhibitor to microbial activity, affecting the efficacy of the biological treatment of wastewater. This review aims to 1) identify the major biodegradable components in saline fish wastewater that may result in deleterious effects upon discharge, 2) discuss the current methods used for the treatment of fish processing wastewaters, and 3) identify opportunities for improved processes to be utilised and identify gaps in knowledge that require further research. Total suspended solids (TSS), chemical oxygen demand (COD), biochemical oxygen demand (BOD), and total nitrogen (TN) were found to be the most prevalent components in fish effluent. High concentrations of TSS and TN are likely due to the protein content. One method for reducing the environmental impact of the treated wastewater is to enhance nutrient removal (TSS, TN, BOD) through process modification, leading to an increase in active proteolytic activity. Bioaugmentation using immobilised, saline-tolerant proteases or halophilic, protease-producing microorganisms have both shown significant potential in laboratory studies in reducing both the COD and TN content of fish processing wastewater to below discharge limits and therefore may represent commercial options for future treatment processes.

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Separation, biochemical characterization and salt‐tolerant mechanisms of alkaline protease from Aspergillus oryzae

Cited by 32 publications

References 31 publications

Comparative study on the novel umami‐active peptides of the whole soybeans and the defatted soybeans fermented soy sauce

Comparative study on the novel umami‐active peptides of the whole soybeans and the defatted soybeans fermented soy sauce

Stability comparison of four lipases and catalytic mechanism during the synthesis of 1,3‐di‐oleic‐2‐medium chain triacylglycerols in a trace water‐in‐oil system: Experimental analyses and computational simulations

Options for Improved Treatment of Saline Wastewater From Fish and Shellfish Processing

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